It has been hitherto known that metals or metal compounds react with atmospheric oxygen in the presence of water, and various disoxidants utilizing this principle have been proposed. In this case, as the metals or metal compounds, there have been used a wide variety of metals or metal compounds including, for example, iron, copper, manganese, zinc, nickel, aluminum, chromium, ferrosilicon, ferronickel, ferromanganese, iron carbide, iron sulfide, ferrous oxide, ferrous hydroxide, iron carbonyl, silicon iron, ferrous acetate, sodium sulfide, ferrous carbon, and the like. In general, any metals or metal compounds, so long as they are capable of being oxidized, is applicable singly or in the form of a mixture. Such metals or metal compounds, however, are slow in the rate at which they react with atmospheric oxygen and, therefore, are generally used in combination with various electrolytes used as a promoter. In this case, the disoxidation reaction activity of the metals or metal compounds may vary depending upon the kind of electrolytes used therewith. It has generally been believed that halogenated metals exhibit the most excellent disoxidation activity among them, and that oxyacid salts such as sulfates or nitrates are inferior and are not practical in actual use.